This invention relates to a method of forming the building using the wooden structural member.
Many buildings are formed from wooden frames which is then coated or covered on the inside and outside surfaces with suitable sheathing material. The wood frame buildings include a floor plate, a plurality of vertical wall studs arranged at horizontally spaced positions to thus form a vertical wall and a top plate for the wall. In most cases a roof structure is applied which also includes ceiling joists and roof trusses.
In most cases the joists and studs are formed from solid lumber and in imperial measure these structural members are nominally formed as two inches by four inches or two inches by six inches et cetera. In practice of course after planing these sizes are reduced so that a nominal 2.times.4 has a conventional dimension of the order of 1.5 inches by 3.5 inches.
For many years wooden frame buildings of this type used wall studs which are simply 2.times.4 and joists which are suitably dimensioned depending upon the intended size of the building. However solid lumber of this type has a number of disadvantages.
Firstly solid lumber is a relatively poor insulating material so that there is significant communication of heat from the inside edge of the lumber adjacent the warm interior outwardly to the outside surface of the lumber which is adjacent the cold exterior.
Secondly the solid lumber divides the wall into separated compartments so that there is no possibility of communication from one compartment to the next and therefore it is necessary to cut or drill holes in the studs for transmission of services to the building such as the electrical wiring.
Thirdly it is becoming more difficult to provide single pieces of lumber in the wider widths now required over a full length of the lumber in view of logging practices. The reduced availability therefore of the full size of the lumber in the length and width directions provides a significant increase in cost relative to the basic volume of wood required for the structural member. Thus solid wood structural member of for example 2.times.12 is significantly more expensive than two pieces of 2.times.6.
The formation of trusses using two strips of lumber is of course well known. Examples of these devices are shown in U.S. Pat. Nos. 4,372,093 (Ericsson); 4,741,139 (Campbell); 4,485,606 (Gottlieb); 4,541,218 (Gottlieb); 4,669,243 (Gore et al); 4,827,688 (Tene). However trusses of this type can be relatively expensive in view of the expense of the hardware involved. In addition the hardware provides a significant quantity of metal for communication of heat through the structural member. Trusses of this type have therefore achieved little success in the construction field. Trusses used as floor joists involving an upper strip and a lower strip which are connected by plywood which is rebated into a slot within the upper and lower strips has become more widely used but is solely used as floor joists and is particularly used for the greater accuracy and structural rigidity which is obtained which reduces movement, flexing and noise from the floor structure. Problems of this type however are of limited value in the formation of walls.